The term “abrasive brush” refers to an abrasive material which comprises a main body of the brush and a large number of filaments extending from the main body and exerts an abrasive function through rubbing a workpiece with the filaments. The “filament” refers to a fibrous member, which has a small sectional area, and is long and easy to bend.
An abrasive brush may comprise a plurality of members. For example, an abrasive brush may be constituted by fastening a member composed of bundled filaments to a main body having a handle, a mounting part, etc. This is because making a module of filaments apart from a main body will make it easy to vary the shape of an abrasive brush depending on the use thereof. In this specification, a component of an abrasive brush in which filaments are bundled is referred to as an abrasive brush member. A main body to which an abrasive brush member is to be mounted is referred to as a support member.
FIG. 20 is a schematic view showing an example of the structure of a conventional linear abrasive brush member, wherein (a) is a perspective view and (b) is a cross-sectional view. With reference to FIG. 20 (b), in a linear abrasive brush member, fibers 2 are folded in half across the core 1 and the folded parts are fastened by caulking with a U-shaped metal sleeve 3 and 4.
FIG. 21 is a schematic view showing an example of a process for producing a linear abrasive brush member. A core 1 is placed on the center of fibers 2. A roller 5 presses the core 1 to fold the fibers 2 and simultaneously inserts the fibers 2 into a metal sleeve 4. The folded part of the fibers 2 is fastened together with the metal sleeve 4 from both sides with a knurling tool 6, thereby being fixed.
A linear abrasive brush member comprises a long, thin substrate part to which filaments are fixed and a plurality of filaments which project from a side surface of the long, thin substrate part in about parallel. An abrasive brush is produced by deforming the linear abrasive brush member or fixing the substrate part thereof to a properly shaped supporting member. The supporting member used is, for example, a cylindrical shape or a disk shape.
However, there are the following problems in conventional linear abrasive brush members. Since fibers are fastened with a metal sleeve by caulking, filaments tend to break due to application of load on the caulked part. The production requires complicated works and a large cost because the number of constituent parts is large. Abrasion ability is weak because filaments are thin and cylindrical.
Japanese Patent Kohyo Publication No. 2001-502185 (WO96/33638) discloses, as other conventional examples, an abrasive brush and abrasive brush member comprising a substrate part and filament parts integrally molded from a composition containing a thermoplastic elastomer as a major component. A plurality of the abrasive brushes are usually layered and used as an abrasive brush.
Japanese Patent Kohyo Publication No. 2001-502185 (WO96/33638) discloses that a wheel-shaped abrasive brush or a disk-shaped abrasive brush is fabricated using the integrally molded abrasive brush members as a part.
In Japanese Patent Kohyo Publication No. 2001-502185 (WO96/33638), abrasive brush members are molded while their dimensions or shapes are determined in advance so as to be commensurate with driving members or supporting members to which they are mounted. In such abrasive brush members, when it becomes necessary to change the external shape or dimensions of an abrasive brush fabricated, the dimensions or shape of the abrasive brush members should be changed first and a metal mold have to be redesigned and produced again. Therefore, abrasive brushes using the abrasive brush members integrally molded from a resin require much labor and costs for changing their external shapes or dimensions.
U.S. Pat. No. 3,233,272 discloses an abrasive brush member comprising a substrate part and filament parts integrally molded from flexible plastics. The material of the abrasive brush member disclosed in patent document 2 is not a thermoplastic elastomer and thus is insufficient in elasticity. Therefore, the filament parts are easily broken and the substrate part is inferior in deformability. The substrate part is insufficient in strength, and is inferior in safety for using high-speed rotational abrasive brushes.
Japanese Patent Kohyo Publication No. 2001-502185 (WO96/33638) and U.S. Pat. No. 3,233,272 disclose that a wheel-shaped abrasive brush or a disk-shaped abrasive brush is fabricated with integrally molded abrasive brush members as a part.